Wellbores are drilled to locate and produce hydrocarbons by advancing a drilling tool coupled to a drill bit into the ground. Drilling and other downhole tools may be provided with and/or coupled to one or more devices operable downhole to sample fluid from the surrounding formation. The drilling tool may be removed and a wireline tool may be deployed into the wellbore to sample fluid from the formation. Samples are collected in one or more sample chambers positioned in the downhole drilling or wireline tool. The sample chambers may be mounted near the outer perimeter of a collar of the tool to facilitate their removal on the rig floor. However, the tool collar may be subjected to rotational bending and other stresses during operations.